JPH0649543B2 - Media sheet transport device - Google Patents

Description

Description: (a) Field of Industrial Application The present invention relates to a media sheet transporting device for continuously feeding a roll-shaped media sheet, and particularly to adjusting the transport speed of the media sheet during the transport thereof. The present invention relates to an improvement of a media sheet conveying device provided with a buffer roller for performing the above.

(b) Conventional technology using a media sheet coated with microcapsules containing a photocurable substance and a color-forming dye, and an image-receiving sheet coated with a developer that causes the color-forming dye to develop color,
There is a method for forming an image (JP-A-58-88739, etc.). In this method, the media sheet is imagewise exposed, and then the image receiving sheet is superposed on the exposed part and pressed to destroy the uncured microcapsules (the microcapsules that were not exposed to light), and A color image is formed and a color image is formed on the image receiving sheet.

Conventionally, the above-mentioned media sheet is wound around a supply shaft in a roll shape and housed in a media cartridge so as to be shielded from stray light. Then, it is taken up from the media cartridge and wound around the take-up shaft via the exposure section where the image forming light is irradiated and the pressure transfer section where the image receiving sheet is superposed and pressed. By the way, the exposure of the media sheet,
When pressure transfer is performed, the optimum exposure speed and the optimum pressure transfer speed are different. In general, the optimum pressure transfer speed is faster, for example, about 10 times the optimum exposure speed. Therefore, conventionally, a movable buffer roller is provided while the rolled media sheet is being conveyed, and the exposure speed and the pressure transfer speed can be freely set by moving the buffer roller.

FIG. 5 is a schematic view of a media sheet transporting device equipped with a buffer roller, in which the media sheet 52 pulled out from the media roll 51 is passed through a transport roller 53, a buffer roller 55, and a pressure roller 56 to a take-up shaft 57. Being rolled up. The buffer roller 55 is movable in the directions of arrows A and B in the figure. When the buffer roller 55 moves in the direction of arrow A, image exposure is performed in the exposure section P1, and when it moves in the direction of arrow B, pressure transfer is performed in the pressure transfer section P2. Done. By setting the speed when the buffer roller 55 moves in the direction of arrow A to 1/2 of the optimum exposure speed and the speed when moving in the direction of arrow B to 1/2 of the optimum pressure transfer speed, The conveyance speed of the media sheet at the time of pressure transfer can be made almost optimal. In the figure, 54 is a buffer roller 55.
Is a guide roller that reverses the conveyance direction of the media sheet when the media sheet moves in the directions of arrows A and B.

(c) Problems to be Solved by the Invention By the way, as shown in FIG. 5, the buffer roller 55 is conventionally the exposure unit P1, the guide roller 54, and the buffer roller 5.
The movement control was performed with the position where 5 is substantially linear as the home position. This is because the media roll 51 is detachably provided in the main body of the image forming apparatus, and when a new media roll is mounted in the main body of the image forming apparatus, the leading end of the media sheet 51 is automatically conveyed by the conveying roller 53 and the exposing section P1. , The guide roller 54, the buffer roller 55, and the pressure roller 56, and is wound around the winding shaft 57 (auto loading), and the media sheet 52 is substantially linear between the guide roller 54 and the buffer roller 55. This is because jamming of the media sheet (JAM) or the like will occur unless it is kept in the same shape.

When the buffer roller 55 moves in the direction of the arrow A to carry the media sheet 52, the media sheet carrying speed is 1 / 2v1 (v1: buffer roller moving speed) shortly after the start of carrying. However, immediately after the start of the movement in the direction of arrow A, the conveyance speed of the media sheet becomes slightly slower than the movement speed v1 of the buffer roller 55 by the arc of the guide roller 54, and the conveyance speed of the media sheet becomes unstable. turn into. Therefore, there is a problem that the conveyance speed of the media sheet and the exposure speed at the exposure part P1 do not match, and the image quality of the formed image is blurred.

An object of the present invention is to provide a media sheet transporting device capable of performing smooth loading at the time of automatic loading and performing accurate pull-out control at the time of pulling out a media sheet by improving the movement control of the buffer roller. Especially.

(d) Means for Solving the Problems The present invention draws out a media sheet from a media roll in which the media sheet is formed into a roll, and winds the media sheet through an exposure unit, a guide roller, and a movably supported buffer roller. In a media sheet transport device that pulls out a media sheet from a media roll by winding it around a take-up shaft and moving the buffer roller, the media sheet is made substantially linear between the exposure section, the guide roller, and the buffer roller. A first buffer roller control means for moving the buffer roller to a position where the buffer roller moves, and a buffer roller image exposure start position near the intersection point where the center line in the moving direction of the buffer roller and the center line of the guide roller intersect vertically. Second buffer roller control means for controlling the movement of the The is characterized in that provided.

(e) Operation In the media sheet transporting device of the present invention, when the media roll is mounted on the main body of the image forming apparatus, if the buffer roller is controlled by the first buffer roller control means, the exposure unit, the guide roller, the buffer roller Since the media sheet becomes substantially linear in the interval, it suffices to linearly feed the leading edge of the media sheet when performing auto-loading, and it is difficult for JAM to occur in the media sheet.

Further, when the buffer roller is controlled by the second buffer roller control means when pulling out the media sheet, the image exposure start position of the buffer roller vertically intersects the center line of the guide roller and the center line of movement of the buffer roller. Since it is set near the intersection, the feeding speed of the media sheet does not become unstable due to the arc of the guide roller at the start of movement of the buffer roller at the time of exposure. It will be sent.

(f) Embodiment FIG. 3 is a schematic front view of a copying machine using a media sheet conveying device according to an embodiment of the present invention.

An original table 11 for placing an original to be copied is provided on the upper surface of the copying machine main body 1, and an optical system 12 including a light source, a mirror, a lens and the like is provided below the original table 11. The optical system 12 scans the document on the document table 11 and guides the reflected light to an exposure unit described later to expose the media sheet.

A pair of pressure rollers 13 that are pressed into contact with each other is arranged at a substantially central portion of the copying machine main body 1. The pressure roller 13 is pressed against a high pressure of about 90 kg / cm by a pressing mechanism including a spring. A bucket 2 for accommodating a media cartridge is provided on the left side of the pressure roller 13. The bucket 2 has a box shape without a lid, and the slider 2
By a and 2b, it can be pulled out to the front of the copying machine body (toward the front in the figure).

FIG. 4 is an external view showing a state in which the bucket 2 is pulled out to the front surface of the copying machine main body 1. A media cartridge 3 is mounted in the box-shaped bucket 2. The media cartridge 3 includes a supply shaft 3a and a winding shaft 3b. An unused media sheet 31 is wound around the supply shaft 3a to form a media roll. This media roll
It is protected by a frame of the media cartridge and a sheet 32 for blocking light so that it is not exposed to stray light, but an opening 33 is formed at one end thereof so that the media sheet 31 can be fed out. It has become. A roller 34 is provided in the opening 33, and the tip of the media sheet is locked to the roller 34 when the media cartridge is new. The media cartridge 3 can be attached to and detached from the bucket 2 in the vertical direction. When exchanging the media cartridge 3, first, the bucket 2 is pulled out from the copying machine main body 1 to the front side, the media cartridge 3 is taken out upward, and then a new media cartridge is mounted. it can. Further, the bucket 2 is provided with a lock mechanism including a solenoid and the like (not shown), and the supply shaft 3 is provided when necessary.
Lock a to stop the feeding of the media sheet.

A transport sprocket 21 is provided on the upper right portion of the bucket 2. The transport sprocket 21 is provided with protruding guides 21a at both ends of a rotatable roller. On the other hand, the holes 21b are formed on both sides of the media sheet 31.
Are formed. The hole 21b is engaged with the guide 21 and the transport sprocket 21 is rotated to feed the media sheet 31 out of the media cartridge 3. When the media cartridge 3 is mounted in the bucket 2, the user pulls out the media sheet 31 that is engaged on the roller 34, and engages the transport sprocket 21 with the hole 21b at the tip thereof. This work can be easily performed because the bucket 2 is pulled out to the front surface of the copying machine main body 1, and does not burden the user.

A rotary gear (not shown) is provided on the back surface of the transport sprocket 21, and when the bucket 2 is pushed into the copying machine main body 1, it meshes with a gear on the copying machine main body side. A drive system is connected to the gear on the main body side of the copying machine via a clutch, and the clutch is turned on during the automatic loading of the media sheet to transmit the drive force to the transport sprocket 21. A knob 21c is provided on the front surface of the transport sprocket 21, and is used when the media sheet is replaced or when the media sheet is jammed.

Sensors S1 and S2 are provided at the bucket insertion portion of the copying machine main body 1. The sensor S1 is provided above the bucket 2 at a position facing the media sheet 31, and detects the presence or absence of the media sheet 31. The sensor S2 is provided below the bucket 2 and detects whether or not the bucket 2 is attached to the copying machine main body 1.

The media sheet 31 delivered from the media cartridge 3 has the above-described transport sprocket 21, exposure unit P1,
Guide roller 41, buffer roller 42, transport roller 1
4, it is wound around the winding shaft 3b via the pressure transfer portion P2 between the pressure rollers 13 and the conveying roller 15. As described above, the transport sprocket 21 is connected to a drive system (not shown),
Rotate during auto loading. Buffer roller 42
A buffer motor capable of rotating in both forward and reverse directions is connected to the via a clutch and moves in the directions of arrows A and B in the figure. The pressure roller 13 is also connected to a drive system (not shown) via a clutch and rotates during pressure transfer. In addition,
An area on the upper right portion of the buffer roller 42, which is indicated by a chain double-dashed line in the figure, is a buffer portion in which the media sheet on which the selectively cured image is formed is stocked.

As described above, the reflected light of the original is guided to the exposure section P1 by the optical system 12, and the media sheet 31 is exposed. The buffer roller 42 is movable in the directions of arrows A and B in the figure, and when the media sheet 31 is exposed in the exposure unit P1, it is moved in the direction of arrow A by the rotation of the buffer motor to move from the media cartridge 3 to the media sheet 3.
Roll out 1. Further, when pressure transfer is performed, the media sheet is pulled by the rotation of the pressure roller 13, the buffer roller 42 moves in the direction of arrow B, and the media sheet on which the selectively cured image is formed is sent to the pressure transfer portion P2. A paper cassette 17 is provided on the right side of the copying machine main body 1, and an image receiving sheet is fed from one of the paper cassettes when pressure transfer is performed. The image receiving sheet is superposed on the selectively cured image on the media sheet and is pressed by the pressure roller 13 to form a color image.

FIGS. 1A to 1C are schematic views showing the process of conveying the media sheet 31.

First, FIG. 3A is a diagram showing a state in which the media sheet 31 that has been manually pulled out to the transport sprocket 21 is then automatically loaded. The buffer roller 42 is moved to the loading position (hereinafter referred to as RP) by the first buffer roller control means. This RP includes an exposure section P1, a guide roller 41,
The RP sensor for detecting the presence or absence of the buffer roller is provided at a position where the media sheet 31 passing through the buffer roller 42 is set to be substantially linear.
Media sheet 31 pulled out from the media roll
Has its tip hooked on the transport sprocket 21 as described above.
The guide roller 41 and the buffer roller 4 are automatically loaded by rotation of a conveying system such as a pressure roller.
2, the pressure roller 13 and the roller 14 are wound around the winding shaft 3b. A portion of the main sheet 31 having a predetermined length from the tip is made of a resin sheet having elasticity, and is easily sent out by the appraisal of the transport sprocket 21 and the like. Further, a paper guide 16 is provided along the conveyance path of the media sheet, and the media sheet 31 is fed along the conveyance path during automatic loading.

FIGS. 9B and 9C are diagrams showing the operating state of the buffer roller during image formation. Buffer roller 42 during image formation
Are controlled by the second control means. That is, the image exposure start position (hereinafter referred to as SP) of the buffer roller 42 is set at a position where the center line of the moving direction of the buffer roller 42 and the center line of the guide roller 41 intersect perpendicularly, and with this HP as the reference. The buffer roller 42 is controlled to move in the directions of arrows A and B according to the forming process. The SP is provided with an SP sensor that detects the presence or absence of a buffer roller.

When the media sheet is exposed in the exposure section P1, as shown in FIG.
Moves in the direction of arrow A with SP as a reference, whereby the media sheet 31 is pulled out. Then, in the exposure portion P1, the light reflected from the original document is applied to the media sheet 31, and the microcapsules on the media sheet 31 are partially cured to form a selectively cured image. After the irradiation of the document reflected light onto the media sheet 31 is completed, and a media sheet slightly longer than the length between the exposure portion P1 and the pressure transfer portion P2 is sent to the buffer portion, the buffer roller 42 moves in the direction of arrow A. Movement stops. This extra feed amount is necessary so that the rear end of the image forming area (area where the selectively cured image is formed) reaches the downstream side (with respect to the media sheet conveyance direction) of the pressure roller 13 when the pressure transfer is completed. It is the amount of withdrawal. During exposure, the pressure roller 13
Does not rotate.

When the exposure process in the exposure part P1 is completed, the pressure transfer process is started in the pressure transfer part P2. As shown in FIG. 6C, the pressure roller 13 rotates to pull the media sheet 31, which causes the buffer roller 42 to move in the direction of arrow B to feed the media sheet 31 to the winding shaft 3b. It will be rolled up. At this time, the image receiving sheet is superposed on the selectively cured image of the media sheet 31. Both the media sheet and the image receiving sheet are pressed by the pressure roller 13 at the pressure transfer portion P2,
The uncured microcapsules are destroyed, and the colorless dye that has flowed out forms a color image on the image receiving sheet. As described above, a media sheet longer than the distance between the exposure part P1 and the pressure transfer part P2 is sent to the buffer part behind the selectively cured image, and the buffer roller 4
When 2 returns to SP, the trailing edge of the selectively cured image is located at the pressure transfer portion P2.

Image formation is performed by moving the buffer roller 42 in the directions of arrows A and B as described above. As described above, since the HP of the buffer roller 42 is set at the intersection of the center line of the buffer roller moving direction and the center line of the guide roller, the conveyance speed of the media sheet is unstable at the start of the movement in the arrow A direction. It never becomes.

FIG. 2 is a flow chart showing the processing procedure of media sheet conveyance. FIG. 2A shows the processing procedure at the time of automatic loading, and FIG. 2B shows the processing procedure at the time of image formation.

First, the procedure in which the buffer roller is controlled by the first buffer roller control means and the media sheet is automatically loaded will be described.

When the sensor S2 for determining the presence / absence of the bucket 2 is turned off, the flowchart shown in FIG. S2
Indicates that the bucket 2 has been pulled out from the copying machine main body 1, during which the media cartridge 3 is replaced. When the media cartridge 3 is replaced and the bucket 2 is inserted into the copying machine main body 1, n
It is determined that the sensors S1 and S2 are turned on in 1 and n2. When the sensors S1 and S2 are turned on, it means that the front end of the media sheet 31 is pulled out from the media cartridge 3 and hung on the transport sprocket 21, and the process proceeds to the auto loading process.

The buffer roller 42 is normally stopped at the SP, and it is moved to the RP before auto loading. That is, the buffer motor is rotated in the reverse direction and the clutch of the buffer roller is turned on to move the buffer roller 42 in the direction of arrow B (n3 → n4). When the buffer roller 42 moves to RP and the RP sensor is turned on (n5), the clutch is turned off, the buffer motor is stopped (n6, n7), and the buffer roller 42 is stopped at RP. As a result, as shown in FIG. 1A, the exposure section P1, the guide roller 4
1, the media sheet is substantially linear between the buffer rollers 42, and the media sheet is fed in a substantially straight line at the time of automatic loading, so that the occurrence of JAM can be prevented.

When the buffer roller 42 is moved to the RP, the media sheet conveying system is turned on and the timer is started. This timer measures the time during which the media sheet 31 hung on the carrying sprocket 21 is carried to the take-up shaft 3b. When the media sheet transport system is turned on, the transport sprocket 21, the pressure roller 13 and the like rotate, and the media sheet is automatically loaded. When the timer times out (n10), the media sheet transport system is turned off to stop the transport sprocket, the pressure roller, etc. (n11), and the automatic loading of the media sheet is completed.

Then, the buffer roller 42 is returned to the SP, and the processing ends. That is, the buffer roller 42 is moved in the direction of arrow A by rotating the buffer motor in the forward direction and then turning on the clutch (n12 → n13).
When SP reaches SP and the SP sensor is turned on (n14), the clutch is turned off and the buffer motor is stopped (n15, n16) to stop the buffer roller 42 at SP.

As described above, automatic loading is performed when the media sheet is replaced.

Next, when the image forming process is performed by the second buffer roller control means, as shown in FIG. 2B, when the print switch provided in the main body of the copying machine is operated, the media sheet is conveyed. The control of is started.

When the print switch is turned on, the supply shaft 3a of the media cartridge 3 is unlocked (n21), the buffer motor is normally rotated and the buffer roller clutch is turned on, and the media sheet 31 is fed out from the media cartridge 3 ( n22 → n23). A document on the document table 11 is scanned in parallel with the feeding of the media sheet, and the reflected light is guided to the exposure unit P1 to expose the media sheet 31, and a selectively cured image is formed on the media sheet. When the exposure is completed (n24), the timer is started at n25. This timer measures the time for which the media sheet 31 feeds a slightly larger amount of the media sheet than the length between the exposure section P1 and the pressure transfer section P2.
That is, extra drawing is performed so that the rear end of the selectively cured image reaches the downstream of the pressure transfer portion P2 when the image forming process is completed. If the timer times out (n2
6) The clutch of the buffer roller and the buffer motor are turned off to stop the feeding of the media sheet (27, 28), and the supply shaft 3a of the media cartridge 3 is locked (n29).

When the exposure is completed as described above, the pressure transfer is performed next. The pressure roller 13 is turned on by turning on the clutch of the pressure roller.
Is rotated (n30). Then, the media sheet in the buffer portion is pulled and the buffer roller 42 moves in the direction of arrow B, and the media sheet 31 is gradually bitten by the pressure roller 13 and pressed. At this time, the image receiving sheet is superposed on the selectively cured image of the media sheet 31, the uncured microcapsules are destroyed by the pressure, and a colored image is formed on the image receiving sheet. When the buffer roller 42 reaches SP (n31), the clutch of the pressure roller is turned off and the pressure roller 13 is stopped. At this time, the trailing edge of the selectively cured image on the media sheet reaches the downstream side of the pressure roller 13, and the pressure transfer in the image forming area is completed.

The SP of the buffer roller may be set on the right side (FIG. 3) of the intersection of the center line of the buffer roller moving direction and the center line of the guide roller. Even in that case, when the buffer roller moves in the direction of arrow A. From the start of movement, the media sheet is accurately fed at 1/2 speed of the movement speed of the buffer roller, and the conveyance speed does not become unstable.

(g) Effect of the Invention As described above, according to the present invention, when the buffer roller is controlled by the first buffer roller control means during the automatic loading of the media sheet, the media sheet is formed between the exposure unit, the guide roller and the buffer roller. Since it is substantially linear, the leading edge of the media sheet is easily fed, and JAM of the media sheet does not occur.

Further, when the buffer roller is controlled by the second buffer roller control means during image formation, the image exposure start position is set at an appropriate position, and the media sheet conveyance speed becomes unstable when the media sheet is pulled out. It does not occur, and the exposure image (selective cured image) does not blur.

[Brief description of drawings]

FIG. 1 is a diagram showing a state of a buffer roller of a media sheet conveying device according to an embodiment of the present invention. FIG. 1 (A) shows a state at the time of automatic loading, FIG.
(C) shows a state during image formation. FIG. 2 is a flow chart showing the processing procedure of the device.
Shows a processing procedure at the time of auto-loading, and FIG. 7B shows a processing procedure at the time of image formation. FIG. 3 is a schematic front view of a copying machine to which the same apparatus is applied, and FIG. 4 is a perspective view of a media sheet storage section. Further, FIG. 5 is a schematic view of a conventional media sheet conveying device. 3 ... Media cartridge, 3b ... Winding shaft, 13 ... Pressure roller, 14, 15 ... Conveying roller, 31 ... Media sheet, 41 ... Guide roller, 42 ... Buffer roller, RP ... Loading position , SP …… Image exposure start position.

Claims (1)

[Claims] 1. A media sheet is pulled out from a media roll in a roll shape, and is wound around a winding shaft via an exposure unit, a guide roller, and a movably supported buffer roller. In the media sheet conveying device that pulls out the media sheet from the media roll by moving the roller, the buffer roller is moved to a position where the media sheet becomes substantially linear between the exposure unit, the guide roller, and the buffer roller. The first buffer roller control unit controls the movement of the buffer roller by setting the image exposure start position of the buffer roller at the vicinity of the intersection point where the center line of the moving direction of the buffer roller and the center line of the guide roller intersect perpendicularly. La control means and are provided. Deer sheet conveying device.